Water quality investigation and control measures of Yudong reservoir and its effluent Guazhai River

By water quality investigation and evaluation of Yudong reservoir and its effluent Guazhai River,it was concluded that the main reason of pH value exceeding the standard was ineffective control of internal and external sources of total nitrogen and total phosphorus pollutant.The nutrient entered reservoir with runoff for long time.Uncontrolled growth of algae and lack of Ca2+ leaded to pH value exceeding the standard under the condition of high-temperature, light,total nitrogen,total phosphorus and other adequate conditions.The Yudong reservoir effluent had the trend of further deterioration of water quality.The control countermeasures of reduction of endogenous and exogenous pollution were proposed.